arch/powerpc/platforms/cell/interrupt.c - LeafOS-Devices/android_kernel_realme_mt6785 - Gitiles

 /*
  * Cell Internal Interrupt Controller
  *
  * Copyright (C) 2006 Benjamin Herrenschmidt (benh@kernel.crashing.org)
  *                    IBM, Corp.
  *
  * (C) Copyright IBM Deutschland Entwicklung GmbH 2005
  *
  * Author: Arnd Bergmann <arndb@de.ibm.com>
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation; either version 2, or (at your option)
  * any later version.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  *
  * TODO:
  * - Fix various assumptions related to HW CPU numbers vs. linux CPU numbers
  *   vs node numbers in the setup code
  * - Implement proper handling of maxcpus=1/2 (that is, routing of irqs from
  *   a non-active node to the active node)
  */

 #include <linux/interrupt.h>
 #include <linux/irq.h>
 #include <linux/module.h>
 #include <linux/percpu.h>
 #include <linux/types.h>
 #include <linux/ioport.h>

 #include <asm/io.h>
 #include <asm/pgtable.h>
 #include <asm/prom.h>
 #include <asm/ptrace.h>
 #include <asm/machdep.h>

 #include "interrupt.h"
 #include "cbe_regs.h"

 struct iic {
 	struct cbe_iic_thread_regs __iomem *regs;
 	u8 target_id;
 	u8 eoi_stack[16];
 	int eoi_ptr;
 	struct device_node *node;
 };

 static DEFINE_PER_CPU(struct iic, iic);
 #define IIC_NODE_COUNT	2
 static struct irq_host *iic_host;

 /* Convert between "pending" bits and hw irq number */
 static irq_hw_number_t iic_pending_to_hwnum(struct cbe_iic_pending_bits bits)
 {
 	unsigned char unit = bits.source & 0xf;
 	unsigned char node = bits.source >> 4;
 	unsigned char class = bits.class & 3;

 	/* Decode IPIs */
 	if (bits.flags & CBE_IIC_IRQ_IPI)
 		return IIC_IRQ_TYPE_IPI | (bits.prio >> 4);
 	else
 		return (node << IIC_IRQ_NODE_SHIFT) | (class << 4) | unit;
 }

 static void iic_mask(unsigned int irq)
 {
 }

 static void iic_unmask(unsigned int irq)
 {
 }

 static void iic_eoi(unsigned int irq)
 {
 	struct iic *iic = &__get_cpu_var(iic);
 	out_be64(&iic->regs->prio, iic->eoi_stack[--iic->eoi_ptr]);
 	BUG_ON(iic->eoi_ptr < 0);
 }

 static struct irq_chip iic_chip = {
 	.typename = " CELL-IIC ",
 	.mask = iic_mask,
 	.unmask = iic_unmask,
 	.eoi = iic_eoi,
 };


 static void iic_ioexc_eoi(unsigned int irq)
 {
 }

 static void iic_ioexc_cascade(unsigned int irq, struct irq_desc *desc,
 			    struct pt_regs *regs)
 {
 	struct cbe_iic_regs __iomem *node_iic = (void __iomem *)desc->handler_data;
 	unsigned int base = (irq & 0xffffff00) | IIC_IRQ_TYPE_IOEXC;
 	unsigned long bits, ack;
 	int cascade;

 	for (;;) {
 		bits = in_be64(&node_iic->iic_is);
 		if (bits == 0)
 			break;
 		/* pre-ack edge interrupts */
 		ack = bits & IIC_ISR_EDGE_MASK;
 		if (ack)
 			out_be64(&node_iic->iic_is, ack);
 		/* handle them */
 		for (cascade = 63; cascade >= 0; cascade--)
 			if (bits & (0x8000000000000000UL >> cascade)) {
 				unsigned int cirq =
 					irq_linear_revmap(iic_host,
 							  base | cascade);
 				if (cirq != NO_IRQ)
 					generic_handle_irq(cirq, regs);
 			}
 		/* post-ack level interrupts */
 		ack = bits & ~IIC_ISR_EDGE_MASK;
 		if (ack)
 			out_be64(&node_iic->iic_is, ack);
 	}
 	desc->chip->eoi(irq);
 }


 static struct irq_chip iic_ioexc_chip = {
 	.typename = " CELL-IOEX",
 	.mask = iic_mask,
 	.unmask = iic_unmask,
 	.eoi = iic_ioexc_eoi,
 };

 /* Get an IRQ number from the pending state register of the IIC */
 static unsigned int iic_get_irq(struct pt_regs *regs)
 {
 	struct cbe_iic_pending_bits pending;
 	struct iic *iic;
 	unsigned int virq;

 	iic = &__get_cpu_var(iic);
 	*(unsigned long *) &pending =
 		in_be64((unsigned long __iomem *) &iic->regs->pending_destr);
 	if (!(pending.flags & CBE_IIC_IRQ_VALID))
 		return NO_IRQ;
 	virq = irq_linear_revmap(iic_host, iic_pending_to_hwnum(pending));
 	if (virq == NO_IRQ)
 		return NO_IRQ;
 	iic->eoi_stack[++iic->eoi_ptr] = pending.prio;
 	BUG_ON(iic->eoi_ptr > 15);
 	return virq;
 }

 #ifdef CONFIG_SMP

 /* Use the highest interrupt priorities for IPI */
 static inline int iic_ipi_to_irq(int ipi)
 {
 	return IIC_IRQ_TYPE_IPI + 0xf - ipi;
 }

 void iic_setup_cpu(void)
 {
 	out_be64(&__get_cpu_var(iic).regs->prio, 0xff);
 }

 void iic_cause_IPI(int cpu, int mesg)
 {
 	out_be64(&per_cpu(iic, cpu).regs->generate, (0xf - mesg) << 4);
 }

 u8 iic_get_target_id(int cpu)
 {
 	return per_cpu(iic, cpu).target_id;
 }
 EXPORT_SYMBOL_GPL(iic_get_target_id);

 struct irq_host *iic_get_irq_host(int node)
 {
 	return iic_host;
 }
 EXPORT_SYMBOL_GPL(iic_get_irq_host);


 static irqreturn_t iic_ipi_action(int irq, void *dev_id)
 {
 	int ipi = (int)(long)dev_id;

 	smp_message_recv(ipi);

 	return IRQ_HANDLED;
 }
 static void iic_request_ipi(int ipi, const char *name)
 {
 	int virq;

 	virq = irq_create_mapping(iic_host, iic_ipi_to_irq(ipi));
 	if (virq == NO_IRQ) {
 		printk(KERN_ERR
 		       "iic: failed to map IPI %s\n", name);
 		return;
 	}
 	if (request_irq(virq, iic_ipi_action, IRQF_DISABLED, name,
 			(void *)(long)ipi))
 		printk(KERN_ERR
 		       "iic: failed to request IPI %s\n", name);
 }

 void iic_request_IPIs(void)
 {
 	iic_request_ipi(PPC_MSG_CALL_FUNCTION, "IPI-call");
 	iic_request_ipi(PPC_MSG_RESCHEDULE, "IPI-resched");
 #ifdef CONFIG_DEBUGGER
 	iic_request_ipi(PPC_MSG_DEBUGGER_BREAK, "IPI-debug");
 #endif /* CONFIG_DEBUGGER */
 }

 #endif /* CONFIG_SMP */


 static int iic_host_match(struct irq_host *h, struct device_node *node)
 {
 	return device_is_compatible(node,
 				    "IBM,CBEA-Internal-Interrupt-Controller");
 }

 static int iic_host_map(struct irq_host *h, unsigned int virq,
 			irq_hw_number_t hw)
 {
 	switch (hw & IIC_IRQ_TYPE_MASK) {
 	case IIC_IRQ_TYPE_IPI:
 		set_irq_chip_and_handler(virq, &iic_chip, handle_percpu_irq);
 		break;
 	case IIC_IRQ_TYPE_IOEXC:
 		set_irq_chip_and_handler(virq, &iic_ioexc_chip,
 					 handle_fasteoi_irq);
 		break;
 	default:
 		set_irq_chip_and_handler(virq, &iic_chip, handle_fasteoi_irq);
 	}
 	return 0;
 }

 static int iic_host_xlate(struct irq_host *h, struct device_node *ct,
 			   u32 *intspec, unsigned int intsize,
 			   irq_hw_number_t *out_hwirq, unsigned int *out_flags)

 {
 	unsigned int node, ext, unit, class;
 	const u32 *val;

 	if (!device_is_compatible(ct,
 				     "IBM,CBEA-Internal-Interrupt-Controller"))
 		return -ENODEV;
 	if (intsize != 1)
 		return -ENODEV;
 	val = get_property(ct, "#interrupt-cells", NULL);
 	if (val == NULL || *val != 1)
 		return -ENODEV;

 	node = intspec[0] >> 24;
 	ext = (intspec[0] >> 16) & 0xff;
 	class = (intspec[0] >> 8) & 0xff;
 	unit = intspec[0] & 0xff;

 	/* Check if node is in supported range */
 	if (node > 1)
 		return -EINVAL;

 	/* Build up interrupt number, special case for IO exceptions */
 	*out_hwirq = (node << IIC_IRQ_NODE_SHIFT);
 	if (unit == IIC_UNIT_IIC && class == 1)
 		*out_hwirq |= IIC_IRQ_TYPE_IOEXC | ext;
 	else
 		*out_hwirq |= IIC_IRQ_TYPE_NORMAL |
 			(class << IIC_IRQ_CLASS_SHIFT) | unit;

 	/* Dummy flags, ignored by iic code */
 	*out_flags = IRQ_TYPE_EDGE_RISING;

 	return 0;
 }

 static struct irq_host_ops iic_host_ops = {
 	.match = iic_host_match,
 	.map = iic_host_map,
 	.xlate = iic_host_xlate,
 };

 static void __init init_one_iic(unsigned int hw_cpu, unsigned long addr,
 				struct device_node *node)
 {
 	/* XXX FIXME: should locate the linux CPU number from the HW cpu
 	 * number properly. We are lucky for now
 	 */
 	struct iic *iic = &per_cpu(iic, hw_cpu);

 	iic->regs = ioremap(addr, sizeof(struct cbe_iic_thread_regs));
 	BUG_ON(iic->regs == NULL);

 	iic->target_id = ((hw_cpu & 2) << 3) | ((hw_cpu & 1) ? 0xf : 0xe);
 	iic->eoi_stack[0] = 0xff;
 	iic->node = of_node_get(node);
 	out_be64(&iic->regs->prio, 0);

 	printk(KERN_INFO "IIC for CPU %d target id 0x%x : %s\n",
 	       hw_cpu, iic->target_id, node->full_name);
 }

 static int __init setup_iic(void)
 {
 	struct device_node *dn;
 	struct resource r0, r1;
 	unsigned int node, cascade, found = 0;
 	struct cbe_iic_regs __iomem *node_iic;
 	const u32 *np;

 	for (dn = NULL;
 	     (dn = of_find_node_by_name(dn,"interrupt-controller")) != NULL;) {
 		if (!device_is_compatible(dn,
 				     "IBM,CBEA-Internal-Interrupt-Controller"))
 			continue;
 		np = get_property(dn, "ibm,interrupt-server-ranges", NULL);
 		if (np == NULL) {
 			printk(KERN_WARNING "IIC: CPU association not found\n");
 			of_node_put(dn);
 			return -ENODEV;
 		}
 		if (of_address_to_resource(dn, 0, &r0) ||
 		    of_address_to_resource(dn, 1, &r1)) {
 			printk(KERN_WARNING "IIC: Can't resolve addresses\n");
 			of_node_put(dn);
 			return -ENODEV;
 		}
 		found++;
 		init_one_iic(np[0], r0.start, dn);
 		init_one_iic(np[1], r1.start, dn);

 		/* Setup cascade for IO exceptions. XXX cleanup tricks to get
 		 * node vs CPU etc...
 		 * Note that we configure the IIC_IRR here with a hard coded
 		 * priority of 1. We might want to improve that later.
 		 */
 		node = np[0] >> 1;
 		node_iic = cbe_get_cpu_iic_regs(np[0]);
 		cascade = node << IIC_IRQ_NODE_SHIFT;
 		cascade |= 1 << IIC_IRQ_CLASS_SHIFT;
 		cascade |= IIC_UNIT_IIC;
 		cascade = irq_create_mapping(iic_host, cascade);
 		if (cascade == NO_IRQ)
 			continue;
 		/*
 		 * irq_data is a generic pointer that gets passed back
 		 * to us later, so the forced cast is fine.
 		 */
 		set_irq_data(cascade, (void __force *)node_iic);
 		set_irq_chained_handler(cascade , iic_ioexc_cascade);
 		out_be64(&node_iic->iic_ir,
 			 (1 << 12)		/* priority */ |
 			 (node << 4)		/* dest node */ |
 			 IIC_UNIT_THREAD_0	/* route them to thread 0 */);
 		/* Flush pending (make sure it triggers if there is
 		 * anything pending
 		 */
 		out_be64(&node_iic->iic_is, 0xfffffffffffffffful);
 	}

 	if (found)
 		return 0;
 	else
 		return -ENODEV;
 }

 void __init iic_init_IRQ(void)
 {
 	/* Setup an irq host data structure */
 	iic_host = irq_alloc_host(IRQ_HOST_MAP_LINEAR, IIC_SOURCE_COUNT,
 				  &iic_host_ops, IIC_IRQ_INVALID);
 	BUG_ON(iic_host == NULL);
 	irq_set_default_host(iic_host);

 	/* Discover and initialize iics */
 	if (setup_iic() < 0)
 		panic("IIC: Failed to initialize !\n");

 	/* Set master interrupt handling function */
 	ppc_md.get_irq = iic_get_irq;

 	/* Enable on current CPU */
 	iic_setup_cpu();
 }
	/*
	* Cell Internal Interrupt Controller
	*
	* Copyright (C) 2006 Benjamin Herrenschmidt (benh@kernel.crashing.org)
	* IBM, Corp.
	*
	* (C) Copyright IBM Deutschland Entwicklung GmbH 2005
	*
	* Author: Arnd Bergmann <arndb@de.ibm.com>
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License as published by
	* the Free Software Foundation; either version 2, or (at your option)
	* any later version.
	*
	* This program is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	* GNU General Public License for more details.
	*
	* You should have received a copy of the GNU General Public License
	* along with this program; if not, write to the Free Software
	* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
	*
	* TODO:
	* - Fix various assumptions related to HW CPU numbers vs. linux CPU numbers
	* vs node numbers in the setup code
	* - Implement proper handling of maxcpus=1/2 (that is, routing of irqs from
	* a non-active node to the active node)
	*/

	#include <linux/interrupt.h>
	#include <linux/irq.h>
	#include <linux/module.h>
	#include <linux/percpu.h>
	#include <linux/types.h>
	#include <linux/ioport.h>

	#include <asm/io.h>
	#include <asm/pgtable.h>
	#include <asm/prom.h>
	#include <asm/ptrace.h>
	#include <asm/machdep.h>

	#include "interrupt.h"
	#include "cbe_regs.h"

	struct iic {
	struct cbe_iic_thread_regs __iomem *regs;
	u8 target_id;
	u8 eoi_stack[16];
	int eoi_ptr;
	struct device_node *node;
	};

	static DEFINE_PER_CPU(struct iic, iic);
	#define IIC_NODE_COUNT 2
	static struct irq_host *iic_host;

	/* Convert between "pending" bits and hw irq number */
	static irq_hw_number_t iic_pending_to_hwnum(struct cbe_iic_pending_bits bits)
	{
	unsigned char unit = bits.source & 0xf;
	unsigned char node = bits.source >> 4;
	unsigned char class = bits.class & 3;

	/* Decode IPIs */
	if (bits.flags & CBE_IIC_IRQ_IPI)
	return IIC_IRQ_TYPE_IPI \| (bits.prio >> 4);
	else
	return (node << IIC_IRQ_NODE_SHIFT) \| (class << 4) \| unit;
	}

	static void iic_mask(unsigned int irq)
	{
	}

	static void iic_unmask(unsigned int irq)
	{
	}

	static void iic_eoi(unsigned int irq)
	{
	struct iic *iic = &__get_cpu_var(iic);
	out_be64(&iic->regs->prio, iic->eoi_stack[--iic->eoi_ptr]);
	BUG_ON(iic->eoi_ptr < 0);
	}

	static struct irq_chip iic_chip = {
	.typename = " CELL-IIC ",
	.mask = iic_mask,
	.unmask = iic_unmask,
	.eoi = iic_eoi,
	};


	static void iic_ioexc_eoi(unsigned int irq)
	{
	}

	static void iic_ioexc_cascade(unsigned int irq, struct irq_desc *desc,
	struct pt_regs *regs)
	{
	struct cbe_iic_regs __iomem node_iic = (void __iomem )desc->handler_data;
	unsigned int base = (irq & 0xffffff00) \| IIC_IRQ_TYPE_IOEXC;
	unsigned long bits, ack;
	int cascade;

	for (;;) {
	bits = in_be64(&node_iic->iic_is);
	if (bits == 0)
	break;
	/* pre-ack edge interrupts */
	ack = bits & IIC_ISR_EDGE_MASK;
	if (ack)
	out_be64(&node_iic->iic_is, ack);
	/* handle them */
	for (cascade = 63; cascade >= 0; cascade--)
	if (bits & (0x8000000000000000UL >> cascade)) {
	unsigned int cirq =
	irq_linear_revmap(iic_host,
	base \| cascade);
	if (cirq != NO_IRQ)
	generic_handle_irq(cirq, regs);
	}
	/* post-ack level interrupts */
	ack = bits & ~IIC_ISR_EDGE_MASK;
	if (ack)
	out_be64(&node_iic->iic_is, ack);
	}
	desc->chip->eoi(irq);
	}


	static struct irq_chip iic_ioexc_chip = {
	.typename = " CELL-IOEX",
	.mask = iic_mask,
	.unmask = iic_unmask,
	.eoi = iic_ioexc_eoi,
	};

	/* Get an IRQ number from the pending state register of the IIC */
	static unsigned int iic_get_irq(struct pt_regs *regs)
	{
	struct cbe_iic_pending_bits pending;
	struct iic *iic;
	unsigned int virq;

	iic = &__get_cpu_var(iic);
	(unsigned long ) &pending =
	in_be64((unsigned long __iomem *) &iic->regs->pending_destr);
	if (!(pending.flags & CBE_IIC_IRQ_VALID))
	return NO_IRQ;
	virq = irq_linear_revmap(iic_host, iic_pending_to_hwnum(pending));
	if (virq == NO_IRQ)
	return NO_IRQ;
	iic->eoi_stack[++iic->eoi_ptr] = pending.prio;
	BUG_ON(iic->eoi_ptr > 15);
	return virq;
	}

	#ifdef CONFIG_SMP

	/* Use the highest interrupt priorities for IPI */
	static inline int iic_ipi_to_irq(int ipi)
	{
	return IIC_IRQ_TYPE_IPI + 0xf - ipi;
	}

	void iic_setup_cpu(void)
	{
	out_be64(&__get_cpu_var(iic).regs->prio, 0xff);
	}

	void iic_cause_IPI(int cpu, int mesg)
	{
	out_be64(&per_cpu(iic, cpu).regs->generate, (0xf - mesg) << 4);
	}

	u8 iic_get_target_id(int cpu)
	{
	return per_cpu(iic, cpu).target_id;
	}
	EXPORT_SYMBOL_GPL(iic_get_target_id);

	struct irq_host *iic_get_irq_host(int node)
	{
	return iic_host;
	}
	EXPORT_SYMBOL_GPL(iic_get_irq_host);


	static irqreturn_t iic_ipi_action(int irq, void *dev_id)
	{
	int ipi = (int)(long)dev_id;

	smp_message_recv(ipi);

	return IRQ_HANDLED;
	}
	static void iic_request_ipi(int ipi, const char *name)
	{
	int virq;

	virq = irq_create_mapping(iic_host, iic_ipi_to_irq(ipi));
	if (virq == NO_IRQ) {
	printk(KERN_ERR
	"iic: failed to map IPI %s\n", name);
	return;
	}
	if (request_irq(virq, iic_ipi_action, IRQF_DISABLED, name,
	(void *)(long)ipi))
	printk(KERN_ERR
	"iic: failed to request IPI %s\n", name);
	}

	void iic_request_IPIs(void)
	{
	iic_request_ipi(PPC_MSG_CALL_FUNCTION, "IPI-call");
	iic_request_ipi(PPC_MSG_RESCHEDULE, "IPI-resched");
	#ifdef CONFIG_DEBUGGER
	iic_request_ipi(PPC_MSG_DEBUGGER_BREAK, "IPI-debug");
	#endif /* CONFIG_DEBUGGER */
	}

	#endif /* CONFIG_SMP */


	static int iic_host_match(struct irq_host h, struct device_node node)
	{
	return device_is_compatible(node,
	"IBM,CBEA-Internal-Interrupt-Controller");
	}

	static int iic_host_map(struct irq_host *h, unsigned int virq,
	irq_hw_number_t hw)
	{
	switch (hw & IIC_IRQ_TYPE_MASK) {
	case IIC_IRQ_TYPE_IPI:
	set_irq_chip_and_handler(virq, &iic_chip, handle_percpu_irq);
	break;
	case IIC_IRQ_TYPE_IOEXC:
	set_irq_chip_and_handler(virq, &iic_ioexc_chip,
	handle_fasteoi_irq);
	break;
	default:
	set_irq_chip_and_handler(virq, &iic_chip, handle_fasteoi_irq);
	}
	return 0;
	}

	static int iic_host_xlate(struct irq_host h, struct device_node ct,
	u32 *intspec, unsigned int intsize,
	irq_hw_number_t out_hwirq, unsigned int out_flags)

	{
	unsigned int node, ext, unit, class;
	const u32 *val;

	if (!device_is_compatible(ct,
	"IBM,CBEA-Internal-Interrupt-Controller"))
	return -ENODEV;
	if (intsize != 1)
	return -ENODEV;
	val = get_property(ct, "#interrupt-cells", NULL);
	if (val == NULL \|\| *val != 1)
	return -ENODEV;

	node = intspec[0] >> 24;
	ext = (intspec[0] >> 16) & 0xff;
	class = (intspec[0] >> 8) & 0xff;
	unit = intspec[0] & 0xff;

	/* Check if node is in supported range */
	if (node > 1)
	return -EINVAL;

	/* Build up interrupt number, special case for IO exceptions */
	*out_hwirq = (node << IIC_IRQ_NODE_SHIFT);
	if (unit == IIC_UNIT_IIC && class == 1)
	*out_hwirq \|= IIC_IRQ_TYPE_IOEXC \| ext;
	else
	*out_hwirq \|= IIC_IRQ_TYPE_NORMAL \|
	(class << IIC_IRQ_CLASS_SHIFT) \| unit;

	/* Dummy flags, ignored by iic code */
	*out_flags = IRQ_TYPE_EDGE_RISING;

	return 0;
	}

	static struct irq_host_ops iic_host_ops = {
	.match = iic_host_match,
	.map = iic_host_map,
	.xlate = iic_host_xlate,
	};

	static void __init init_one_iic(unsigned int hw_cpu, unsigned long addr,
	struct device_node *node)
	{
	/* XXX FIXME: should locate the linux CPU number from the HW cpu
	* number properly. We are lucky for now
	*/
	struct iic *iic = &per_cpu(iic, hw_cpu);

	iic->regs = ioremap(addr, sizeof(struct cbe_iic_thread_regs));
	BUG_ON(iic->regs == NULL);

	iic->target_id = ((hw_cpu & 2) << 3) \| ((hw_cpu & 1) ? 0xf : 0xe);
	iic->eoi_stack[0] = 0xff;
	iic->node = of_node_get(node);
	out_be64(&iic->regs->prio, 0);

	printk(KERN_INFO "IIC for CPU %d target id 0x%x : %s\n",
	hw_cpu, iic->target_id, node->full_name);
	}

	static int __init setup_iic(void)
	{
	struct device_node *dn;
	struct resource r0, r1;
	unsigned int node, cascade, found = 0;
	struct cbe_iic_regs __iomem *node_iic;
	const u32 *np;

	for (dn = NULL;
	(dn = of_find_node_by_name(dn,"interrupt-controller")) != NULL;) {
	if (!device_is_compatible(dn,
	"IBM,CBEA-Internal-Interrupt-Controller"))
	continue;
	np = get_property(dn, "ibm,interrupt-server-ranges", NULL);
	if (np == NULL) {
	printk(KERN_WARNING "IIC: CPU association not found\n");
	of_node_put(dn);
	return -ENODEV;
	}
	if (of_address_to_resource(dn, 0, &r0) \|\|
	of_address_to_resource(dn, 1, &r1)) {
	printk(KERN_WARNING "IIC: Can't resolve addresses\n");
	of_node_put(dn);
	return -ENODEV;
	}
	found++;
	init_one_iic(np[0], r0.start, dn);
	init_one_iic(np[1], r1.start, dn);

	/* Setup cascade for IO exceptions. XXX cleanup tricks to get
	* node vs CPU etc...
	* Note that we configure the IIC_IRR here with a hard coded
	* priority of 1. We might want to improve that later.
	*/
	node = np[0] >> 1;
	node_iic = cbe_get_cpu_iic_regs(np[0]);
	cascade = node << IIC_IRQ_NODE_SHIFT;
	cascade \|= 1 << IIC_IRQ_CLASS_SHIFT;
	cascade \|= IIC_UNIT_IIC;
	cascade = irq_create_mapping(iic_host, cascade);
	if (cascade == NO_IRQ)
	continue;
	/*
	* irq_data is a generic pointer that gets passed back
	* to us later, so the forced cast is fine.
	*/
	set_irq_data(cascade, (void __force *)node_iic);
	set_irq_chained_handler(cascade , iic_ioexc_cascade);
	out_be64(&node_iic->iic_ir,
	(1 << 12) /* priority */ \|
	(node << 4) /* dest node */ \|
	IIC_UNIT_THREAD_0 /* route them to thread 0 */);
	/* Flush pending (make sure it triggers if there is
	* anything pending
	*/
	out_be64(&node_iic->iic_is, 0xfffffffffffffffful);
	}

	if (found)
	return 0;
	else
	return -ENODEV;
	}

	void __init iic_init_IRQ(void)
	{
	/* Setup an irq host data structure */
	iic_host = irq_alloc_host(IRQ_HOST_MAP_LINEAR, IIC_SOURCE_COUNT,
	&iic_host_ops, IIC_IRQ_INVALID);
	BUG_ON(iic_host == NULL);
	irq_set_default_host(iic_host);

	/* Discover and initialize iics */
	if (setup_iic() < 0)
	panic("IIC: Failed to initialize !\n");

	/* Set master interrupt handling function */
	ppc_md.get_irq = iic_get_irq;

	/* Enable on current CPU */
	iic_setup_cpu();
	}